Developing Management Techniques For Black Walnut to Stabilize the Annual Nut Supply
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In: 92d Annual Report of the Northern Nut Growers Association; 2001 August 5-8; Cornell, NY. [Cornell, NY: Northern Nut Growers Association]: 60-69
Two studies involving cultural methods to increase nut production of plantation black walnut are presented. In the first study, nut production was measured for 5 years to determine the effect of nitrogen (N) and potassium (K) fertilization separately, in combination, and with and without phosphorus (P) broadcast annually for 4 years at two rates. Fertilization significantly (P > 0.05) increased nut production. Treatments containing P with N and/or K were most effective for nut production. Doubling the rate of application did not cause a corresponding increase in nut production. The alternate bearing tendency that was present in year 3 of the study was not apparent in years 4 and 5. In the second study, we measured the effect of three levels of broadcast N fertilization (0 or control, 100 lbs/ac, 150 lbs/ac elemental N) and two levels of foliar applied boron (B) (with and without) on nut production and nutrition of plantation black walnut. Boron (3 lbs Solubor?/100 gals of water/ac) was sprayed on trees in the early catkin stage in a split plot arrangement. Whole plot treatments were the three rates of ammonium nitrate that were broadcast around trees in mid April and again in mid August. Leaf samples were collected in mid June and again in mid August for nutrient analyses. Nut production was higher for treatments with B compared to treatments without B, and leaf B concentration in samples collected in August increased for trees treated with B. There was an increase in leaf N for the highest N treatment, but nut production was not increased for any N rate.
Ponder, Felix, Jr.; Jones, James E.; Mueller, Rita. 2001. Developing Management Techniques For Black Walnut to Stabilize the Annual Nut Supply. In: 92d Annual Report of the Northern Nut Growers Association; 2001 August 5-8; Cornell, NY. [Cornell, NY: Northern Nut Growers Association]: 60-69